Author Topic: Need "flying wire" probes for small feature PCB probing?  (Read 2152 times)

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Offline FaringdonTopic starter

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Need "flying wire" probes for small feature PCB probing?
« on: December 17, 2022, 10:59:15 pm »
Hi,
AYK, when you probe a PCB with small chips and res/caps on it, you have to solder a "flying wire" to the 0603 resistor or whatever , and then clip the scope to that flying wire.

We do this with a twisted pair of kynar wire, ..but then find the scope cannot be connected to the stripped ends of the kynar as the kynar is too thin.......but we need it thin so we can solder the other end  correctly to the small feature PCB......so therefore we solder 2cm pieces of 0.7mm tinned copper wire to the kynar ends, and then connect the scope probe "hat" and gnd clip to these 0.7mm pieces.

..However, the 0.7mm tinned copper wire pieces keep falling off.

We have thought of wrapping the kynar round the tinned copper wire, (then soldering it to the 0.7mm) and also wrapping some of the kynar insulation too.....then taping that to the tinned copper wire (or heatshrinking it), but that will mean ages spent making such probes.

Is there anything offtheshelf like this?
We searched but cant find.
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Offline alm

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Re: Need "flying wire" probes for small feature PCB probing?
« Reply #1 on: December 17, 2022, 11:27:30 pm »
The big scope manufacturers like Lecroy, Keysight and Tektronix have been making active probes with solder down tips for a while. I don't know if the B brands like Rigol have caught up with these yet. These tips provide optimal signal integrity, but you probably won't like the prices.

As intermediate, good passive probes will have (optional) adapters to 50 25 mil square pin connectors, which can be connected to small grabbers such as the EZ-Hook XKM series that will grab better to thin wires.
« Last Edit: December 17, 2022, 11:42:55 pm by alm »
 
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Online tautech

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Re: Need "flying wire" probes for small feature PCB probing?
« Reply #2 on: December 17, 2022, 11:32:28 pm »
The big scope manufacturers like Lecroy, Keysight and Tektronix have been making active probes with solder down tips for a while. I don't know if the B brands like Rigol have caught up with these yet. These tips provide optimal signal integrity, but you probably won't like the prices.

As intermediate, good passive probes will have (optional) adapters to 50 mil square pin connectors, which can be connected to small grabbers such as the EZ-Hook XKM series that will grab better to thin wires.
25 mil actually is the standard grabber size.  ;)
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Offline alm

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Re: Need "flying wire" probes for small feature PCB probing?
« Reply #3 on: December 17, 2022, 11:53:04 pm »
25 mil actually is the standard grabber size.  ;)

You're right, fixed.

Does Siglent have solutions for solder in probes, or passive probe to 25 mil square pin adapters that have prices not quite as eye-watering as the A brands?
« Last Edit: December 17, 2022, 11:55:19 pm by alm »
 
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Online Martin72

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Re: Need "flying wire" probes for small feature PCB probing?
« Reply #4 on: December 17, 2022, 11:58:50 pm »
Hi,

I got these ones :

https://warwickts.com/1298/PJP-6800-KIT-Micro-Pincer-SMD-Clip-Kits

They are very, very small...Post pics later on.

 
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Online Martin72

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Re: Need "flying wire" probes for small feature PCB probing?
« Reply #5 on: December 18, 2022, 12:08:31 am »
Additional:
I remember at our lab one of our engineers got this from sensepeek:

https://www.batronix.com/shop/measurement/pcb-holder/sensepeek/4019-PCBite-kit-SP200.html

Directly connection to the scope (probes 100 or 200Mhz) and the needle tips are really like a needle...

Can make pics from it next week.

« Last Edit: December 18, 2022, 12:10:44 am by Martin72 »
 
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Online tautech

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Re: Need "flying wire" probes for small feature PCB probing?
« Reply #6 on: December 18, 2022, 12:26:56 am »
25 mil actually is the standard grabber size.  ;)

You're right, fixed.

Does Siglent have solutions for solder in probes, or passive probe to 25 mil square pin adapters that have prices not quite as eye-watering as the A brands?
No but there are some bits and bobs that come with their $ active probes:
https://siglentna.com/products/accessories/probes/active-probes/
Check the manuals for the lists of accessories.

In the past I've cobbled various solutions together at basically zero cost for personal use but now we keep a couple of Pintek's Pro model probe in stock just for the accessories they come with:
Won't attach as a pic:
http://www.pintek.com.tw/customer/pintek/product/CP-3501R-PRO-b.jpg
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Online tautech

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Re: Need "flying wire" probes for small feature PCB probing?
« Reply #7 on: December 18, 2022, 12:48:08 am »
If the PCB density is not too high 25 mil square pin can be soldered instead of wires and flying leads with 25 mill crimp on sockets used for connect.
Fitting SMD test points are the proper way to design in the first instance for which 0805 can be easily hooked onto with scope probes or if you need higher density go to smaller and use grabbers.
Trace clearances are the only restrictions to dropping a SMD test point pad onto the PSC in the layout stage.
https://www.keyelco.com/category.cfm/Test-Points-Tips-Probes-Clips/Test-Points-Surface-Mount/id/523
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Online Martin72

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Re: Need "flying wire" probes for small feature PCB probing?
« Reply #8 on: December 18, 2022, 09:51:58 am »
Quote
They are very, very small...Post pics later on.

Really small... ;)

 
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Offline alm

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Re: Need "flying wire" probes for small feature PCB probing?
« Reply #9 on: December 18, 2022, 01:13:03 pm »
Sigrok has a nice comparison of clips. But the main problem here is how to hook up the clips to a scope probe. Many passive probes either come with or have optional twin-lead adapters that adapt them to square pin connectors, but apparently not Siglent or Rigol probes. Probe tip sizes, and the dimension and location of the grounding sleeve, are not universal, so using adapters from other brands is a gamble.

There is nothing complicated about these, but the probe tip connector is uncommon, and you want a minimum of bulk, weight, and length, so something like a probe tip to BNC adapter, then a BNC socket, and then wires is sub-optimal.
 
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Offline JehTeh

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Re: Need "flying wire" probes for small feature PCB probing?
« Reply #10 on: December 18, 2022, 09:33:22 pm »
I have a collection of sensepeek probes that I really can't recommend enough. They offer passive scope probes up to 500MHz, as well as just low speed 'DMM' pogo probes, and they all work fantastic

I use them often on boards with 0.5mm QFPs and lots of 0402 components with zero issues. I have not had to solder on a test lead in ages.

 
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Offline Faranight

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Re: Need "flying wire" probes for small feature PCB probing?
« Reply #11 on: December 19, 2022, 06:24:27 am »
Oh yeah! Sensepeek all the way. Gets a recommendation from me as well. I have zero regrets buying it :-+
https://easyengineering.eu/wp-content/uploads/2022/09/200126_Sensepeek39125_head-1024x1024.jpg
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Offline Nusa

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Re: Need "flying wire" probes for small feature PCB probing?
« Reply #12 on: December 19, 2022, 07:25:50 am »
I'd just pull out my old wire wrap tool and wrap wires to square header pins. They're close enough to wire wrap pins to work, and that's what kynar wire was used for in the first place, way back when.
 
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Offline David Hess

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Re: Need "flying wire" probes for small feature PCB probing?
« Reply #13 on: December 19, 2022, 04:12:19 pm »
I use 30 gauge kynar insulated wire wrap wire for the same thing.  Better oscilloscope probes have no difficulty grabbing it, and there are micro sized oscilloscope probes which are better yet.
 
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Offline Mechatrommer

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Re: Need "flying wire" probes for small feature PCB probing?
« Reply #14 on: December 19, 2022, 04:48:34 pm »
Oh yeah! Sensepeek all the way. Gets a recommendation from me as well. I have zero regrets buying it :-+
https://easyengineering.eu/wp-content/uploads/2022/09/200126_Sensepeek39125_head-1024x1024.jpg
of course we seldomly regret buying expensive stuffs... btw i made my own probes (2nd prototype.. those with colored rings) the grabbers can perfectly grab directly to smd components, but i dont feel like damaging them with many clip unclip and wiggles, so flying wires there are...
Nature: Evolution and the Illusion of Randomness (Stephen L. Talbott): Its now indisputable that... organisms “expertise” contextualizes its genome, and its nonsense to say that these powers are under the control of the genome being contextualized - Barbara McClintock
 
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Offline luudee

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Re: Need "flying wire" probes for small feature PCB probing?
« Reply #15 on: December 20, 2022, 04:31:31 am »
I made my own adopters for the tiny clips.

 
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